Control method of electric vehicle, motor controller and electric vehicle

Abstract

The invention provides a control method of an electric vehicle, a motor controller and the electric vehicle. The control method is used for achieving starting redundant steering of the electric vehicle and comprises the steps that the opening degree of an accelerator pedal and the steering angle of a steering wheel of the electric vehicle are detected; and at the first moment after the opening degree of an accelerator pedal of the electric vehicle is increased from zero to be larger than the preset opening degree and the leftward turning angle of the steering wheel is increased from zero to be larger than the first preset turning angle, a driving motor of the electric vehicle is controlled to drive the electric vehicle to run, and a rear wheel steering mechanism of the electric vehicle is controlled to turn rightwards. By means of the control method, redundant steering of the vehicle can be achieved through the rear wheel steering mechanism, and the safety and reliability of vehicle driving are guaranteed.

Description

Technical Field

[0001] The present application relates to the field of vehicles, and in particular to a control method for an electric vehicle, a motor controller and an electric vehicle. Background Art

[0002] The vehicle's steering system is an important part of the chassis, which determines the safety, stability and driving comfort of the vehicle's steering. Reasonable steering control plays an important role in reducing traffic accidents and ensuring people's personal safety. The vehicle's redundant steering system is one of the key technologies for intelligent connected vehicles to achieve autonomous steering, path tracking and obstacle avoidance. It directly affects the vehicle's active safety and driving experience, and is one of the cornerstones for achieving advanced driving and intelligent chassis. However, the current redundant steering system is mainly designed for front-wheel steering, ignoring the coordinated control of the rear-wheel steering mechanism, and cannot give full play to the vehicle's steering performance. Summary of the invention

[0003] The present application provides a control method for an electric vehicle, a motor controller and an electric vehicle. When the vehicle starts or travels, the rear wheel steering mechanism of the vehicle is controlled to adjust the steering angle based on the steering angle of the steering wheel, so that the vehicle can achieve redundant steering through the rear wheel steering mechanism, thereby ensuring the safety and reliability of the vehicle travel.

[0004] In a first aspect, a control method for an electric vehicle is provided, which is used to realize redundant steering when the electric vehicle starts, and the control method comprises: detecting the accelerator pedal opening and the steering wheel angle of the electric vehicle; at a first moment after the accelerator pedal opening of the electric vehicle increases from zero to greater than a preset opening and the steering wheel angle to the left increases from zero to greater than a first preset angle, controlling the drive motor of the electric vehicle to drive the electric vehicle to travel and controlling the rear wheel steering mechanism of the electric vehicle to turn right.

[0005] The preset opening can be understood as a relatively small accelerator pedal opening. When the user steps on the accelerator pedal until the accelerator pedal opening is greater than the preset opening, it can be understood that the user wishes to control the vehicle to start.

[0006] The first preset angle may be understood as any angle within the range of angles supported by the steering wheel. When the user turns the steering wheel to the left until the angle of the steering wheel is greater than the first preset angle, it may be understood that the user wishes to control the vehicle to turn.

[0007] It can be understood that when the front wheel steering mechanism of the electric vehicle is effective, the control method can simultaneously control the active steering of the front and rear wheels of the vehicle, thereby effectively improving the mobility efficiency of the vehicle when starting. When the front wheel steering mechanism of the electric vehicle fails, the control method can control the active steering of the rear wheel steering mechanism, thereby controlling the normal steering of the electric vehicle and improving the robustness of the vehicle when starting.

[0008] It can be understood that in this control method, different first preset angles can be set according to the state of the front wheel steering mechanism of the electric vehicle. Among them, the electric vehicle can be equipped with a fault detection component for detecting whether the function of the front wheel steering mechanism of the vehicle is normal, and sending the detection result to the controller. For example, when the power assist of the front wheel steering mechanism fails or the mechanical connection fails, the fault detection component can send a fault signal to the controller to indicate that the front wheel steering mechanism has failed.

[0009] According to the embodiment of the present application, during the starting process of the electric vehicle, the rear wheel steering mechanism of the vehicle is controlled to adjust the steering angle based on the steering angle of the steering wheel, so that the vehicle can control the active steering of the front and rear wheels of the vehicle when the front wheel steering mechanism is effective, and the vehicle can control the active steering of the rear wheels of the vehicle when the front wheel steering mechanism fails, thereby ensuring the safety and reliability of the steering system of the electric vehicle. Moreover, even when the front wheel steering mechanism fails, the user can still control the vehicle to start steering by turning the steering angle of the steering wheel and operating the opening of the accelerator pedal, without performing additional operations, which is conducive to improving the user's operating experience.

[0010] In combination with the first aspect, in some embodiments of the first aspect, the control method also includes: at the first moment, controlling the rear wheel steering mechanism of the electric vehicle to turn right and controlling the braking system of the electric vehicle to brake the left rear wheel of the electric vehicle.

[0011] In other words, during the redundant steering of the electric vehicle at start-up, the braking system can be controlled to brake and turn the inner rear wheel and control the rear wheel steering mechanism to actively steer, so that the electric vehicle can successfully complete the start-up steering. In these embodiments, through single-side wheel braking and active steering of the rear wheel steering mechanism, a greater yaw acceleration can be provided for the vehicle, so that the vehicle can achieve redundant steering at start-up faster, and improve the vehicle's passability in narrow spaces.

[0012] According to the embodiment of the present application, during the starting process of the electric vehicle, the rear wheel steering mechanism and the braking system of the electric vehicle are coordinated to achieve rapid and stable vehicle steering, thereby improving the vehicle's maneuverability and the vehicle's passability in narrow spaces.

[0013] In combination with the first aspect, in some embodiments of the first aspect, the control method also includes: at a second moment after the first moment, the steering wheel turning angle to the left increases to be greater than a second preset angle, controlling the rear wheel steering mechanism of the electric vehicle to turn right and controlling the braking system of the electric vehicle to brake the left rear wheel of the electric vehicle.

[0014] The second preset angle can be understood as any steering angle within the steering range that is greater than the first preset angle. The user turning the steering wheel so that the steering wheel angle is greater than the second preset angle can be understood as the user expecting to operate the vehicle to start steering at a larger steering angle.

[0015] In the embodiment of the present application, when the steering wheel angle is greater than the first preset angle and less than the second preset angle, the rear wheel steering mechanism and / or the front wheel steering mechanism of the electric vehicle are controlled to realize the redundant steering of the electric vehicle at the start. When the steering wheel angle is greater than the second preset angle, the rear wheel steering mechanism and / or the front wheel steering mechanism of the electric vehicle and the brake system of the electric vehicle are coordinated and controlled to realize the redundant steering of the electric vehicle at the start.

[0016] It can be understood that in this control method, different second preset angles can be set according to the state of the front wheel steering mechanism of the electric vehicle. The second preset angle corresponding to when the front wheel steering mechanism of the electric vehicle is effective can be greater than the second preset angle corresponding to when the front wheel steering mechanism of the electric vehicle fails.

[0017] According to an embodiment of the present application, the rear-wheel steering mechanism and braking system of the vehicle are controlled in sections based on the steering wheel angle. The rear-wheel steering mechanism is controlled to turn when the user's steering demand is small, and the braking system is controlled to intervene when the user's steering demand is large. This can improve driving comfort while reducing the energy consumption caused by the intervention of the braking system, thereby further improving the user experience.

[0018] In combination with the first aspect, in some embodiments of the first aspect, the control method further comprises: at a third moment after the second moment, the steering wheel's leftward turning angle decreases to less than the second preset turning angle, and the brake system is controlled to stop braking the left rear wheel. At a fourth moment after the third moment, the steering wheel's leftward turning angle decreases to less than the first preset turning angle, and the rear wheel steering mechanism is controlled to return to the center.

[0019] It can be understood that during the process of turning and starting the vehicle, the user can adjust the steering angle of the vehicle in real time by turning the steering wheel. The user turns the steering wheel so that the steering angle of the steering wheel to the left is reduced to between the second preset angle and the first preset angle, indicating that the user's steering demand is reduced. In response, the electric vehicle controls the braking system to stop braking the left rear wheel. Further, the user turns the steering wheel so that the steering angle of the steering wheel to the left is reduced to less than the first preset angle, indicating that the user expects the vehicle to stop turning. Therefore, in response, the electric vehicle controls the rear wheel steering mechanism to return to the normal position, so that the electric vehicle can subsequently go straight or perform other steering actions according to the user's operation.

[0020] According to an embodiment of the present application, during the redundant steering process when the vehicle starts, even if the front-wheel steering mechanism of the vehicle fails, the user can accurately adjust the steering angle of the vehicle by controlling the steering wheel. The user's operating burden is low and the practicality of the vehicle's redundant steering function is high.

[0021] In combination with the first aspect, in some embodiments of the first aspect, the control method also includes: between the second moment and the third moment, controlling the braking force output by the braking system to the left rear wheel to increase as the accelerator pedal opening increases, and controlling the steering angle of the rear-wheel steering mechanism to increase as the steering angle of the steering wheel increases.

[0022] According to an embodiment of the present application, during the process of redundant steering when the vehicle starts, the braking force output by the braking system and the steering angle of the rear-wheel steering mechanism are dynamically changed based on the user's operation, thereby further improving the vehicle's controllability and the practicality of the redundant steering function.

[0023] In combination with the first aspect, in some embodiments of the first aspect, the control method further includes: between the first moment and the third moment, controlling the rotation speed of the drive motor to be less than a preset rotation speed. The preset rotation speed can be understood as a safety rotation speed threshold. When the drive motor is controlled to operate at a rotation speed less than the preset rotation speed, the electric vehicle can diagonally travel at a relatively gentle speed.

[0024] According to an embodiment of the present application, during the process of redundant steering when the vehicle starts, by limiting the speed of the drive motor to be less than the safety speed threshold, it is possible to ensure that the vehicle completes the starting steering at a steady speed, thereby further improving the safety of the vehicle.

[0025] In combination with the first aspect, in some embodiments of the first aspect, the control method also includes: between the first moment and the third moment, controlling the driving torque of the left front wheel of the electric vehicle to be smaller than the driving torque of the right front wheel of the electric vehicle.

[0026] It can be understood that in the powertrain with a dual-motor architecture, the motor controller can determine the speed corresponding to the left front wheel and the speed of the motor corresponding to the right front wheel based on the resolver signal, and distribute the torque according to the speed of the motors on both sides, so that the actual yaw moment of the vehicle is better close to the expected yaw moment, ensuring lateral stability and improving steering performance.

[0027] According to the embodiment of the present application, for an electric vehicle with a dual-motor architecture powertrain, when the vehicle starts redundant steering, the drive motor is controlled to output differentiated drive torques to the two front wheels respectively, thereby ensuring the lateral stability of the vehicle during the steering process and further improving the vehicle's handling.

[0028] In combination with the first aspect, in some embodiments of the first aspect, the control method further comprises: between the first moment and the third moment, in response to a slip rate of any wheel of the electric vehicle being greater than a preset slip rate, controlling the corresponding drive motor of any wheel to reduce the torque output. Between the first moment and the third moment, in response to a slip rate of any wheel of the electric vehicle being less than the preset slip rate, controlling the corresponding drive motor of any wheel to increase the torque output.

[0029] It should be emphasized that the closed-loop control of the wheel slip rate mentioned above can be implemented by the motor controller provided in the implementation of this application.

[0030] In the present application, the motor controller in the drive system can calculate the slip rate of the wheel driven by the drive motor according to the speed of the driven drive motor and the output torque of the drive motor. In this way, the observation of whether the wheel is slipping and the adjustment of the slip rate of the wheel are both realized inside the drive system, with a shorter time delay, and can almost achieve microsecond (us) level fast observation and millisecond (ms) level torque adjustment.

[0031] In combination with the first aspect, in some embodiments of the first aspect, the control method also includes: between the first moment and the third moment, in response to the opening of the accelerator pedal decreasing to less than the preset opening, or the opening of the brake pedal of the electric vehicle being greater than the preset brake opening, controlling the drive motor to stop driving the electric vehicle.

[0032] Among them, when the opening of the accelerator pedal decreases to less than the preset opening, it can be understood that the user has released the accelerator pedal and expects to stop the starting process of the electric vehicle. When the opening of the brake pedal is greater than the preset brake opening, it can be understood that the user has stepped on the brake pedal and expects to stop the starting process of the electric vehicle. At this time, in order to respond to the user's operation, the control method provided in this application will control the drive motor 12 to stop driving the electric vehicle.

[0033] It can be understood that when the front wheel steering mechanism is effective, after the electric vehicle is in a parked state, the rear wheel steering mechanism can also be controlled to return to the center position so that the rotation direction of the two rear wheels is consistent with the direction of the vehicle body, reducing the wear on the rear wheel tires.

[0034] According to the embodiment of the present application, when the user wants the electric vehicle to stop, the vehicle can be stopped by releasing the accelerator pedal or stepping on the brake pedal, which is convenient and flexible. Moreover, when the vehicle control system fails to detect the decrease in the accelerator pedal opening in time, the vehicle can still be stopped according to the brake pedal opening, further improving the safety and reliability of the vehicle.

[0035] In a second aspect, a control method for an electric vehicle is provided, the control method being used to realize redundant steering of the electric vehicle during driving, the control method comprising: detecting a steering wheel angle of the electric vehicle during driving of the electric vehicle, and controlling a rear wheel steering mechanism of the electric vehicle to turn right at a first moment after the steering wheel angle to the left increases from zero to greater than a first preset angle.

[0036] It can be understood that during vehicle driving, when the user turns the steering wheel so that the steering wheel turns to the left at a greater angle than the first preset angle, it can be understood that the user desires to control the vehicle to turn left. At this time, the control method provided in the present application will control the rear-wheel steering mechanism to turn right, so that the vehicle establishes a yaw angular velocity to turn left.

[0037] According to the embodiment of the present application, during the driving process of the electric vehicle, the rear wheel steering mechanism of the vehicle is controlled to adjust the steering angle based on the steering angle of the steering wheel, so that the vehicle can control the active steering of the front and rear wheels of the vehicle when the front wheel steering mechanism is effective, and the vehicle can control the active steering of the rear wheels of the vehicle when the front wheel steering mechanism fails, thereby ensuring the safety and reliability of the steering system of the electric vehicle. Moreover, even when the front wheel steering mechanism fails, the user can still control the steering of the vehicle by turning the steering angle of the steering wheel without performing additional operations, which is conducive to improving the user's operating experience.

[0038] In combination with the second aspect, in some embodiments of the second aspect, the control method also includes: at the first moment, controlling the rear wheel steering mechanism of the electric vehicle to turn right, and controlling the braking system of the electric vehicle to brake the left rear wheel of the electric vehicle.

[0039] In other words, during the redundant steering process of the electric vehicle, the braking system can be controlled to brake the inner rear wheel and control the rear wheel steering mechanism to actively steer, so that the electric vehicle can smoothly complete the steering. In these embodiments, through single-side wheel braking and active steering of the rear wheel steering mechanism, a greater yaw acceleration can be provided for the vehicle, so that the vehicle can achieve steering faster and improve the vehicle's maneuverability.

[0040] According to the embodiment of the present application, during the driving process of the electric vehicle, the rear wheel steering mechanism and the braking system of the electric vehicle are coordinated to achieve rapid and stable vehicle steering, thereby improving the vehicle's maneuverability.

[0041] In combination with the second aspect, in some embodiments of the second aspect, the control method further includes: at the first moment, when the speed of the electric vehicle is greater than the preset speed, controlling the drive motor of the electric vehicle to reduce the torque output. At a second moment after the first moment, when the speed of the electric vehicle decreases to less than the preset speed, controlling the rear wheel steering mechanism to turn right, and controlling the braking system to brake the left rear wheel at a third moment after the second moment.

[0042] The preset speed can be understood as a safe speed threshold. For example, the preset speed can be 80 kilometers per hour (kph) or 100 kph, without limitation.

[0043] It can be understood that when the vehicle speed is less than the preset speed, the vehicle can be turned safely by controlling the rear wheel steering mechanism to actively turn. When the vehicle speed is greater than the preset speed, controlling the rear wheel steering mechanism to turn may be risky, so it is necessary to actively control the drive motor 12 to reduce the torque output to slow down the vehicle, and control the rear wheel steering mechanism to complete the turning after the vehicle speed is less than the preset speed.

[0044] According to an embodiment of the present application, during redundant steering of a vehicle, by limiting the rear-wheel steering mechanism to only steer when the vehicle speed is within a safe speed range, it can be ensured that the vehicle can complete the steering safely and smoothly, further improving the safety of the vehicle.

[0045] In combination with the second aspect, in some embodiments of the second aspect, the control method also includes: after the first moment, when the front-wheel steering mechanism of the electric vehicle fails, controlling the vehicle speed of the electric vehicle not to change with the change of the opening of the accelerator pedal when the opening of the accelerator pedal of the electric vehicle is greater than the preset acceleration opening.

[0046] It can be understood that when the accelerator pedal opening is less than or equal to the preset accelerator opening, the electric vehicle can travel within the safe speed range. That is, when the front wheel steering mechanism of the electric vehicle is detected to fail, the speed of the electric vehicle is controlled to maintain a constant rate or a preset rate, and the speed of the electric vehicle is controlled not to increase with the increase of the accelerator pedal opening, thereby ensuring the stability and reliability of the electric vehicle during the U-turn process.

[0047] According to an embodiment of the present application, during redundant steering of a vehicle, when failure of the front wheel steering mechanism of the vehicle is detected, the power output of the vehicle will be actively limited, thereby limiting the speed of the electric vehicle and ensuring the safety of steering of the electric vehicle.

[0048] In a third aspect, a vehicle controller is provided, which is used to execute the control method described in the first aspect or the second aspect, or any embodiment of the first aspect or the second aspect.

[0049] In a fourth aspect, an electric vehicle is provided, comprising a rear-wheel steering mechanism and the controller in the third aspect, wherein the controller is used to control the steering of the rear-wheel steering mechanism.

[0050] For the supplementary and technical effects of the solutions provided in the third and fourth aspects above, please refer to the corresponding descriptions of the first and second aspects and will not be repeated here. BRIEF DESCRIPTION OF THE DRAWINGS

[0051] Figure 1 A schematic diagram of an electric vehicle architecture provided in an embodiment of the present application;

[0052] Figure 2 A schematic diagram of the structure of a braking system and a rear-wheel steering mechanism provided in an embodiment of the present application;

[0053] Figure 3 A schematic diagram of a scenario of redundant steering when starting an electric vehicle provided in an embodiment of the present application;

[0054] Figure 4 A schematic diagram of another scenario of redundant steering when starting an electric vehicle provided in an embodiment of the present application;

[0055] Figure 5 A schematic diagram of the relationship between a preset slip ratio and the output torque of a drive motor provided in an embodiment of the present application;

[0056] Figure 6 A signal timing diagram for controlling redundant steering at vehicle start provided in an embodiment of the present application;

[0057] Figure 7 A signal timing diagram for controlling redundant steering of a vehicle provided in an embodiment of the present application;

[0058] Figure 8 A schematic diagram of the structure of a motor controller provided in an embodiment of the present application. DETAILED DESCRIPTION

[0059] The technical solution in this application will be described below in conjunction with the accompanying drawings.

[0060] In the description of the embodiments of the present application, unless otherwise specified, “ / ” means or. For example, A / B can mean A or B. The “and / or” in this article is merely a way to describe the association relationship of associated objects, indicating that three relationships may exist. For example, A and / or B can mean: A exists alone, A and B exist at the same time, and B exists alone.

[0061] In the embodiments of the present application, prefixes such as "first" and "second" are used only to distinguish different description objects, and have no limiting effect on the position, order, priority, quantity or content of the described objects. The use of prefixes such as ordinal numbers to distinguish description objects in the embodiments of the present application does not constitute a limitation on the described objects. For the statement of the described objects, please refer to the description in the context of the claims or embodiments, and no unnecessary limitation should be constituted due to the use of such prefixes. In addition, in the description of the present embodiment, unless otherwise specified, the meaning of "multiple" is two or more.

[0062] References to "some embodiments" and the like described in this specification mean that a particular feature, structure or characteristic described in conjunction with the embodiment is included in one or more embodiments of the present application. Thus, phrases such as "in some embodiments" and the like that appear at different places in this specification do not necessarily all refer to the same embodiment, but rather mean "one or more but not all embodiments", unless otherwise specifically emphasized. The terms "include", "comprises", "has" and their variations all mean "including but not limited to", unless otherwise specifically emphasized.

[0063] The steering system of a car is an important part of the chassis, which determines the safety, stability and driving comfort of the vehicle's steering. Reasonable steering control plays an important role in reducing traffic accidents and ensuring people's personal safety. The redundant steering system of a car is one of the key technologies for intelligent connected cars to achieve autonomous steering, path tracking and obstacle avoidance. It directly affects the active safety and driving experience of the vehicle, and is one of the cornerstones for achieving advanced driving and intelligent chassis. The design goal of the redundant steering system is to provide main functions such as steering in the event of failure of the vehicle's electronic components or deterioration of the control system environment, so as to ensure that the vehicle operates in a safe manner. Redundant design usually includes redundancy of hardware, communication, power supply and other systems to ensure the continuity and safety of functions.

[0064] In the field of intelligent chassis, redundant design and coordinated control of wire-controlled steering systems are key technologies. The wire-controlled steering system is basically free from mechanical steering, and the signal source may be the chassis domain controller, automatic driving, or direct operation of the driver's steering wheel. Redundant design is a standard configuration of wire-controlled steering. In the absence of direct intervention by the driver and machinery, the redundant system performs backup or performance optimization. Coordinated control makes each wire-controlled mechanism more effective and intelligent.

[0065] However, the current redundant steering system mainly performs redundant control on the front wheel steering, ignoring the control of the rear wheel steering mechanism, and cannot give full play to the steering performance of the vehicle. In addition, if the hardware in the front wheel steering mechanism fails, such as the power loss of the electric power steering system or the mechanical connection failure of the front wheel steering mechanism, the vehicle cannot control the normal steering of the vehicle through the redundant steering system.

[0066] In view of this, the embodiments of the present application provide a control method for an electric vehicle, a motor controller and an electric vehicle. During the driving of the vehicle, the rear wheel steering mechanism of the vehicle is controlled to adjust the steering angle based on the steering angle of the steering wheel, so that the vehicle can achieve redundant steering through the rear wheel steering mechanism when the front wheel steering mechanism fails, thereby ensuring the safety and reliability of the vehicle driving.

[0067] The electric vehicle provided in the embodiments of the present application will be described in detail below in conjunction with specific embodiments.

[0068] See also Figure 1 , Figure 1 A schematic diagram of an electric vehicle 01 provided in an embodiment of the present application. Figure 1 As shown, the electric vehicle 01 includes a drive system 10, a power battery 30 and a brake system 20. The drive system 10 may also be referred to as a powertrain. The drive system 10 is used to drive the electric vehicle 01. The power battery 30 is used to provide electrical energy to the drive system 10. The drive system 10 is used to receive the electrical energy provided by the power battery 30 and provide driving force for the electric vehicle 01. The brake system 20 is used to provide braking force for the electric vehicle 01.

[0069] Optionally, the running state of the electric vehicle 01 includes a driving state and a braking state. Among them, the driving state may refer to the process in which the driving motor 12 of the electric vehicle 01 outputs a positive torque to drive the wheels so that the electric vehicle 01 travels. The braking state may refer to the process in which the braking system 20 outputs a braking force to the wheels of the electric vehicle 01 so that the speed of the electric vehicle 01 gradually decreases. When the electric vehicle 01 is running in the driving state, the driving system 10 is used to output torque to drive the wheels to rotate. When the electric vehicle 01 is running in the braking state, the driving system 10 stops driving the wheels to rotate, and the braking system 20 is used to provide braking force to the wheels so that the electric vehicle 01 reduces the speed under the action of the braking force. Alternatively, in the case where the electric vehicle 01 has an energy recovery function, when the electric vehicle 01 is running in the braking state, the driving system 10 of the electric vehicle 01 can also output a reverse torque to provide feedback braking force for the electric vehicle 01, and the reverse torque output by the driving system 10 can also convert the kinetic energy of the electric vehicle 01 into electrical energy and charge the power battery 30.

[0070] like Figure 1 As shown, the drive system 10 includes a motor controller 11 and a drive motor 12. When the electric vehicle 01 is running in a driving state, the motor controller 11 converts the direct current provided by the power battery 30 into three-phase alternating current, and the three-phase alternating current is used to drive the drive motor 12 to output torque to drive the wheels to rotate. Optionally, the drive motor 12 can output positive torque or reverse torque under the control of the motor controller 11. Among them, outputting positive torque means that the output direction of the drive motor 12 is the same as the rotational speed direction of the drive motor 12, and outputting reverse torque means that the output direction of the drive motor 12 is opposite to the rotational speed direction of the drive motor 12.

[0071] Optionally, the drive system 10 also includes a resolver sensor ( Figure 1 Each motor controller 11 is connected to a resolver sensor through a signal interface. The resolver sensor is used to detect the rotation speed of the drive motor 12 controlled by the motor controller 11. The motor controller 11 is used to receive a resolver signal from the resolver sensor and adjust the rotation speed of the controlled drive motor 12 according to the resolver signal. Exemplarily, the resolver sensor can accurately detect the position, direction and speed of the rotor of the drive motor 12, and is responsible for monitoring and collecting the rotation speed of the drive motor 12.

[0072] Further, when the electric vehicle 01 is a multi-motor electric vehicle, such as a three-motor driven electric vehicle or a four-motor driven electric vehicle, the rotary signal output by the rotary sensor can also be used to indicate the wheel speed of the wheel driven by the drive motor 12. Based on this, the motor controller 11 can directly obtain the corresponding wheel state according to the rotary signal, and calculate the current speed of the electric vehicle according to the wheel speed indicated by the rotary signal. Compared with obtaining the wheel speed of the corresponding wheel through the wheel speed sensor, the sampling rate of the rotary sensor is higher, and it is directly connected to the motor controller 11 by signal, which can shorten the signal transmission link. In the process of the electric vehicle 01 oblique movement, the rotary signal output by the rotary sensor can improve the detection speed of the slip and slip of the wheel. At the same time, the detection and control of the slip and slip of the wheel of the electric vehicle 01 can be completed inside the drive system 10, which can further improve the control stability of the electric vehicle 01 during the oblique movement.

[0073] For example, the braking system 20 in the electric vehicle 01 may be as follows: Figure 2 The braking system 20 includes a brake pedal 21, a brake controller 22, and four wheel-end brake devices 23. When the user steps on the brake pedal 21, the brake controller 22 can generate a brake signal according to the opening of the brake pedal 21, and the four wheel-end brake devices 23 are used to output braking force to the corresponding wheels according to the instructions of the brake signal to reduce the speed of the electric vehicle 01. For example, Figure 2 Taking the direction shown in as an example, the wheel-end brake device 23 at the upper left corner is used to brake the left front wheel LF, the wheel-end brake device 23 at the upper right corner is used to brake the right front wheel RF, the wheel-end brake device 23 at the lower left corner is used to brake the left rear wheel LR, and the wheel-end brake device 23 at the lower right corner is used to brake the right rear wheel RR.

[0074] Optionally, during the braking process of the electric vehicle 01, the greater the opening of the brake pedal 21, the greater the braking force indicated by the braking signal, the greater the braking force output by the four wheel-end brake devices 23, and the faster the speed of the electric vehicle 01 decreases.

[0075] Continue to refer Figure 2 The electric vehicle 01 further includes a rear wheel steering mechanism 40. In the embodiment of the present application, after the user enables the vehicle's diagonal function, the rear wheel steering mechanism 40 can control the two rear wheels of the electric vehicle 01 to rotate to a certain angle. It can be understood that during the diagonal driving of the electric vehicle, the rear wheel steering mechanism 40 can control the two rear wheels to rotate in the same direction as the two front wheels of the electric vehicle, or can control the two rear wheels to rotate in the opposite direction to the two front wheels.

[0076] It should be emphasized that in the embodiment of the present application, the rear-wheel steering mechanism 40 can control the steering angles of the two rear wheels to change synchronously with the steering angle of the front wheels, or can control the steering angles of the two rear wheels to change independently when the steering angle of the front wheels remains unchanged.

[0077] Optionally, the electric vehicle 01 further includes a vehicle control unit (VCU). When the user steps on the accelerator pedal or the accelerator pedal, the VCU can generate a torque signal according to the opening of the accelerator pedal or the accelerator pedal, and send the torque signal to the motor controller 11. After receiving the torque signal, the motor controller 11 controls the drive motor 12 to output torque based on the torque value indicated by the torque signal, thereby driving the electric vehicle 01 to travel.

[0078] In practical applications, the brake controller 22 may be a central controller, a VCU or a domain control unit (DCU), which is not specifically limited in the embodiments of the present application.

[0079] Furthermore, the drive system 10, the brake system 20 and the VCU can be communicatively connected via a controller area network (CAN). Optionally, the VCU can also obtain a driving mode signal via CAN, and the driving mode signal is used to indicate the current driving mode of the electric vehicle 01, for example, the driving mode may include any one of a sports mode, a comfort mode, and an intelligent mode. The VCU can also obtain a gear signal via CAN, and the gear signal is used to indicate the current gear of the electric vehicle 01, for example, the gear may include a forward gear, a reverse gear, etc.

[0080] The above describes the architecture of the electric vehicle provided by the embodiment of the present application. The control method provided by the embodiment of the present application is described in detail below in combination with a specific embodiment. The control method of the electric vehicle provided by the embodiment of the present application can be applied to the redundant steering scenario of the vehicle starting, and can also be applied to the redundant steering scenario of the vehicle driving. The following first describes the control method for the redundant steering scenario of the vehicle starting.

[0081] In some embodiments, the control method includes: detecting the accelerator pedal opening and the steering wheel angle of the electric vehicle 01. At a first moment after the accelerator pedal opening of the electric vehicle 01 increases from zero to a preset opening and the steering wheel angle to the left increases from zero to greater than a first preset angle, controlling the drive motor of the electric vehicle 01 to drive the electric vehicle to travel and controlling the rear wheel steering mechanism 40 of the electric vehicle 01 to turn right.

[0082] It can be understood that during the driving of the electric vehicle, when the user steps on the accelerator pedal of the electric vehicle, the opening of the accelerator pedal increases under the operation of the user. In response to the user's operation, the motor controller can control the torque output by the drive motor to increase according to the opening of the accelerator pedal. Similarly, when the user releases the accelerator pedal, the opening of the accelerator pedal decreases under the operation of the user. In response to the user's operation, the motor controller can control the torque output by the drive motor to decrease according to the opening of the accelerator pedal.

[0083] The preset opening can be understood as a relatively small accelerator pedal opening. When the user steps on the accelerator pedal until the accelerator pedal opening is greater than the preset opening, it can be understood that the user wishes to control the vehicle to start.

[0084] The first preset angle may be understood as any angle within the range of angles supported by the steering wheel. When the user turns the steering wheel to the left until the angle of the steering wheel is greater than the first preset angle, it may be understood that the user wishes to control the vehicle to turn.

[0085] In the embodiment of the present application, when the front wheel steering mechanism of the electric vehicle 01 is effective, the control method can simultaneously control the active steering of the front and rear wheels of the vehicle, thereby effectively improving the moving efficiency of the vehicle when starting. Figure 3 As shown in (a), when the accelerator pedal opening of the electric vehicle 01 is greater than the preset opening and the steering wheel turning angle to the left is greater than the first preset angle, the front wheel steering mechanism of the electric vehicle is controlled to turn left, and the rear wheel steering mechanism of the electric vehicle is controlled to turn right, so that the vehicle turns left to start.

[0086] In the embodiment of the present application, when the front wheel steering mechanism of the electric vehicle 01 fails, the control method can control the rear wheel steering mechanism to actively steer, thereby controlling the electric vehicle 01 to steer normally and improving the robustness of the vehicle starting. Figure 3 As shown in (b), when the accelerator pedal opening of the electric vehicle 01 is greater than the preset opening and the steering wheel turning angle to the left is greater than the first preset angle, the steering angle of the front wheel steering mechanism of the electric vehicle remains unchanged, and the rear wheel steering mechanism of the electric vehicle is controlled to turn right, so that the vehicle turns left to start.

[0087] It can be understood that in this control method, different first preset angles are set according to the state of the front wheel steering mechanism of the electric vehicle 01. Among them, the electric vehicle 01 can be equipped with a fault detection component for detecting whether the function of the front wheel steering mechanism of the vehicle is normal, and sending the detection result to the controller. For example, when the power assist of the front wheel steering mechanism fails or the mechanical connection fails, the fault detection component can send a fault signal to the controller to indicate that the front wheel steering mechanism has failed.

[0088] Exemplarily, the first preset angle corresponding to when the front-wheel steering mechanism of the electric vehicle 01 is effective may be greater than the first preset angle corresponding to when the front-wheel steering mechanism of the electric vehicle 01 fails. Thus, when the front-wheel steering mechanism is effective, the rear-wheel steering mechanism is actively controlled to steer only when the steering angle expected by the user is large, which is conducive to reducing energy consumption. Moreover, when the front-wheel steering mechanism fails, the rear-wheel steering mechanism is actively steered in response to the steering wheel angle to ensure the reliability of the vehicle's redundant steering system.

[0089] Similarly, in some embodiments, the control method further includes: detecting the accelerator pedal opening and the steering wheel angle of the electric vehicle 01. At a first moment after the accelerator pedal opening of the electric vehicle 01 increases from zero to a preset opening and the steering wheel angle to the right increases from zero to greater than a first preset angle, controlling the drive motor of the electric vehicle 01 to drive the electric vehicle to travel and controlling the rear wheel steering mechanism 40 of the electric vehicle 01 to turn left, so that the electric vehicle 01 can turn right to start.

[0090] According to the embodiment of the present application, during the starting process of the electric vehicle, the rear wheel steering mechanism of the vehicle is controlled to adjust the steering angle based on the steering angle of the steering wheel, so that the vehicle can control the active steering of the front and rear wheels of the vehicle when the front wheel steering mechanism is effective, and the vehicle can control the active steering of the rear wheels of the vehicle when the front wheel steering mechanism fails, thereby ensuring the safety and reliability of the steering system of the electric vehicle. Moreover, even when the front wheel steering mechanism fails, the user can still control the vehicle to start steering by turning the steering angle of the steering wheel and operating the opening of the accelerator pedal, without performing additional operations, which is conducive to improving the user's operating experience.

[0091] In some embodiments, the control method further includes: at the first moment, controlling the rear wheel steering mechanism 40 of the electric vehicle 01 to turn right, and controlling the braking system 20 of the electric vehicle 01 to brake the left rear wheel of the electric vehicle 01 .

[0092] In other words, during the redundant steering of the electric vehicle at start-up, the braking system can be controlled to brake and turn the inner rear wheel and control the rear wheel steering mechanism to actively steer, so that the electric vehicle 01 can successfully complete the start-up steering. In these embodiments, through single-side wheel braking and active steering of the rear wheel steering mechanism, a greater yaw acceleration can be provided for the vehicle, so that the vehicle can achieve redundant steering at start-up faster, and improve the vehicle's passability in narrow spaces.

[0093] like Figure 4 As shown in (a), when the front wheel steering mechanism of the electric vehicle 01 is effective, when the accelerator pedal opening of the electric vehicle 01 is greater than the preset opening and the steering wheel turning angle to the left is greater than the first preset angle, the front wheel steering mechanism of the electric vehicle is controlled to turn left, the rear wheel steering mechanism of the electric vehicle is controlled to turn right, and the braking system is controlled to brake the left rear wheel of the electric vehicle, so that the vehicle turns left and starts.

[0094] like Figure 4 As shown in (b), when the front wheel steering mechanism of the electric vehicle 01 fails, when the accelerator pedal opening of the electric vehicle 01 is greater than the preset opening and the steering wheel turning angle to the left is greater than the first preset angle, the steering angle of the front wheel steering mechanism of the electric vehicle remains unchanged, the rear wheel steering mechanism of the electric vehicle is controlled to turn right, and the braking system is controlled to brake the left rear wheel of the electric vehicle, so that the vehicle turns left and starts.

[0095] Likewise, in some embodiments, the control method further includes: at the first moment, controlling the rear wheel steering mechanism 40 of the electric vehicle 01 to turn left, and controlling the braking system 20 of the electric vehicle 01 to brake the right rear wheel of the electric vehicle 01 .

[0096] According to the embodiment of the present application, during the starting process of the electric vehicle, the rear wheel steering mechanism and the braking system of the electric vehicle are coordinated to achieve rapid and stable vehicle steering, thereby improving the vehicle's maneuverability and the vehicle's passability in narrow spaces.

[0097] In some embodiments, the control method also includes: at a second moment after the first moment, the steering wheel's turning angle to the left increases to be greater than a second preset turning angle, controlling the rear wheel steering mechanism 40 of the electric vehicle 01 to turn right and controlling the braking system 20 of the electric vehicle 01 to brake the left rear wheel of the electric vehicle 01.

[0098] The second preset angle can be understood as any steering angle within the steering range that is greater than the first preset angle. The user turning the steering wheel so that the steering wheel angle is greater than the second preset angle can be understood as the user expecting to operate the vehicle to start steering at a larger steering angle.

[0099] In the embodiment of the present application, when the steering wheel angle is greater than the first preset angle and less than the second preset angle, the rear wheel steering mechanism and / or the front wheel steering mechanism of the electric vehicle 01 are controlled to realize the redundant steering at the start of the electric vehicle 01. When the steering wheel angle is greater than the second preset angle, the rear wheel steering mechanism and / or the front wheel steering mechanism of the electric vehicle 01 and the braking system of the electric vehicle 01 are coordinated and controlled to realize the redundant steering at the start of the electric vehicle 01.

[0100] It can be understood that the steering angle of the rear-wheel steering mechanism corresponding to the second preset angle can be less than or equal to the upper limit of the steering of the rear-wheel steering mechanism 40, without limitation. Exemplarily, if the steering angle of the rear-wheel steering mechanism corresponding to the second preset angle is less than the upper limit, then after the second moment, the steering angle of the rear-wheel steering mechanism 40 can be controlled to continue to increase with the increase of the steering wheel angle, and the brake system 20 can be controlled to brake the left rear wheel of the vehicle. Exemplarily, if the steering angle of the rear-wheel steering mechanism corresponding to the second preset angle is equal to the upper limit, then after the second moment, the rear-wheel steering mechanism 40 can be controlled to maintain the steering angle, and the brake system 20 can be controlled to brake the left rear wheel of the vehicle.

[0101] It can be understood that in this control method, different second preset angles are set according to the state of the front wheel steering mechanism of the electric vehicle 01. The second preset angle corresponding to when the front wheel steering mechanism of the electric vehicle 01 is effective can be greater than the second preset angle corresponding to when the front wheel steering mechanism of the electric vehicle 01 is ineffective.

[0102] Similarly, in some embodiments, the control method also includes: at a second moment after the first moment, the steering wheel's turning angle to the right increases to be greater than a second preset turning angle, controlling the rear wheel steering mechanism 40 of the electric vehicle 01 to turn left and controlling the braking system 20 of the electric vehicle 01 to brake the right rear wheel of the electric vehicle 01.

[0103] According to an embodiment of the present application, the rear-wheel steering mechanism and braking system of the vehicle are controlled in sections based on the steering wheel angle. The rear-wheel steering mechanism is controlled to turn when the user's steering demand is small, and the braking system is controlled to intervene when the user's steering demand is large. This can improve driving comfort while reducing the energy consumption caused by the intervention of the braking system, thereby further improving the user experience.

[0104] In some embodiments, the control method further includes: at a third moment after the second moment, the steering wheel's leftward turning angle decreases to less than the second preset turning angle, and the brake system 20 is controlled to stop braking the left rear wheel. At a fourth moment after the third moment, the steering wheel's leftward turning angle decreases to less than the first preset turning angle, and the rear wheel steering mechanism 40 is controlled to return to the center.

[0105] It can be understood that during the process of turning and starting the vehicle, the user can adjust the steering angle of the vehicle in real time by turning the steering wheel. The user turns the steering wheel so that the steering angle of the steering wheel to the left is reduced to between the second preset angle and the first preset angle, indicating that the user's steering demand is reduced. In response, the electric vehicle 01 controls the braking system 20 to stop braking the left rear wheel. Further, the user turns the steering wheel so that the steering angle of the steering wheel to the left is reduced to less than the first preset angle, indicating that the user expects the vehicle to stop turning. Therefore, in response, the electric vehicle 01 controls the rear wheel steering mechanism 40 to return to the center, so that the electric vehicle 01 can go straight or perform other steering actions according to the user's operation in the future.

[0106] It can be understood that in some embodiments, a hysteresis can be set when the steering wheel angle decreases, that is, when the user returns the steering wheel to the right position until the steering wheel angle is less than the second preset angle minus the hysteresis and greater than the first preset angle, the braking system 20 will be controlled to stop braking the left rear wheel. By setting the hysteresis, the probability of user misoperation can be reduced, and the reliability of vehicle redundant steering can be further improved.

[0107] Similarly, in some embodiments, the control method further includes: at a third moment after the second moment, the rightward turning angle of the steering wheel decreases to less than the second preset turning angle, and the brake system 20 is controlled to stop braking the right rear wheel. At a fourth moment after the third moment, the rightward turning angle of the steering wheel decreases to less than the first preset turning angle, and the rear wheel steering mechanism 40 is controlled to return to the center.

[0108] According to an embodiment of the present application, during the redundant steering process when the vehicle starts, even if the front-wheel steering mechanism of the vehicle fails, the user can accurately adjust the steering angle of the vehicle by controlling the steering wheel. The user's operating burden is low and the practicality of the vehicle's redundant steering function is high.

[0109] In some embodiments, the control method also includes: between the second moment and the third moment, controlling the braking force output by the braking system 20 to the left rear wheel to increase as the accelerator pedal opening increases, and controlling the steering angle of the rear-wheel steering mechanism 40 to increase as the steering angle of the steering wheel increases.

[0110] Similarly, in some embodiments, the control method further includes: between the second moment and the third moment, controlling the braking force output by the braking system 20 to the left rear wheel to decrease as the accelerator pedal opening decreases, and controlling the steering angle of the rear wheel steering mechanism 40 to decrease as the steering angle of the steering wheel decreases. That is, during the process of the electric vehicle 01 starting to turn to the left redundantly, controlling the braking force output by the braking system 20 to the left rear wheel to change as the accelerator pedal opening changes, and controlling the steering angle of the rear wheel steering mechanism 40 to change as the steering wheel angle changes.

[0111] It can be understood that during the redundant steering of the electric vehicle 01 at the start, the user can operate the accelerator pedal opening to control the starting speed of the vehicle. Specifically, when the accelerator pedal opening is a preset opening, the braking system 20 can output a braking force to the left rear wheel to provide a yaw torque for the vehicle, thereby accelerating the steering of the vehicle. In the process of the accelerator pedal opening continuing to increase from the preset opening, in order to keep the left rear wheel in a locked state, it is necessary to control the braking force output by the braking system 20 to increase accordingly, thereby avoiding unexpected movement of the vehicle and providing a stable yaw torque for the vehicle, ensuring the stability of the redundant steering of the vehicle. In addition, during the redundant steering of the vehicle at the start, the braking system 20 does not directly output the peak braking force, but controls the braking force to increase with the increase of the accelerator pedal opening, thereby optimizing the energy efficiency of the vehicle.

[0112] It can be understood that during the redundant steering of the electric vehicle 01 at the start, the user can operate the steering wheel to control the steering angle of the vehicle in real time. Exemplarily, when the steering wheel turns leftward at a greater angle than the first preset angle and less than the second preset angle, the rear wheel steering mechanism 40 is controlled to turn rightward at the first angle. When the steering wheel turns leftward at the second preset angle and continues to increase, the rear wheel steering mechanism 40 is controlled to turn rightward at an angle that increases from the first angle as the steering wheel turns leftward.

[0113] In the embodiment of the present application, when the front-wheel steering mechanism of the electric vehicle 01 is effective, the steering angles of the front-wheel steering mechanism and the rear-wheel steering mechanism 40 of the vehicle can be controlled to increase as the steering wheel angle increases, or the steering angle of the front-wheel steering mechanism can be controlled to increase as the steering wheel angle increases, and the steering angle of the rear-wheel steering mechanism 40 can be controlled to increase as the steering angle of the front-wheel steering mechanism increases, thereby ensuring the stability of the vehicle's redundant steering. When the front steering mechanism fails, the steering angles of the rear-wheel steering mechanism 40 can be controlled to increase as the steering wheel angle increases, so that the vehicle can still provide accurate yaw torque in response to the user's operation, ensuring the stability of the vehicle's redundant steering.

[0114] According to an embodiment of the present application, during the process of redundant steering when the vehicle starts, the braking force output by the braking system and the steering angle of the rear-wheel steering mechanism are dynamically changed based on the user's operation, thereby further improving the vehicle's controllability and the practicality of the redundant steering function.

[0115] In some embodiments, the control method further includes: between the second moment and the third moment, controlling the steering angular velocity of the rear-wheel steering mechanism 40 to increase as the steering angle of the steering wheel increases.

[0116] It can be understood that during the redundant steering of the electric vehicle 01 at the start, the user can operate the steering wheel to control the steering angular velocity of the rear-wheel steering mechanism. For example, between the second moment and the third moment, if the user turns the steering wheel so that the steering wheel angle increases from the second preset angle to the third preset angle, the steering angular velocity of the rear-wheel steering mechanism is controlled to be the first angular velocity. If the user turns the steering wheel so that the steering wheel angle increases from the second preset angle to the fourth preset angle, the steering angular velocity of the rear-wheel steering mechanism is controlled to be the second angular velocity. Among them, the third preset angle is less than the fourth preset angle, and the first angular velocity is less than the second angular velocity.

[0117] According to an embodiment of the present application, during the redundant steering process of the vehicle starting, the steering speed of the rear-wheel steering mechanism is controlled to follow the angle at which the user turns the steering wheel, thereby ensuring that the vehicle has a stable steering response time, so that the vehicle can achieve stable and agile steering.

[0118] In some embodiments, the control method further includes: between the first moment and the third moment, controlling the speed of the drive motor 12 to be less than a preset speed. The preset speed can be understood as a safe speed threshold. When the drive motor is controlled to operate at a speed less than the preset speed, the electric vehicle 01 can drive diagonally at a relatively gentle speed.

[0119] Optionally, when the front wheel steering mechanism of the electric vehicle 01 is effective, the speed of the drive motor 12 can be controlled to be greater than the preset speed. That is, when the front wheel steering mechanism of the electric vehicle 01 fails, the speed of the drive motor 12 is controlled to be less than the preset speed.

[0120] Exemplarily, the motor controller in the drive system 10 can receive an acceleration signal from the accelerator pedal and a resolver signal from a resolver sensor, and the resolver signal can be used to indicate the speed of the drive motor driven by the motor controller. In the process of driving the electric vehicle 01 to start redundant steering, the motor controller controls the speed of the drive motor to increase as the opening of the accelerator pedal increases, and the speed of the electric vehicle 01 also increases as the opening of the accelerator pedal increases. When the speed of the drive motor increases to a preset speed, that is, the safety speed threshold is reached, the motor controller can control the speed of the drive motor to maintain at the preset speed, and does not increase with the increase in the opening of the accelerator pedal, so that the electric vehicle 01 can diagonally travel at a relatively gentle and safe speed during the process of starting redundant steering, thereby improving driving safety.

[0121] According to an embodiment of the present application, during the process of redundant steering when the vehicle starts, by limiting the speed of the drive motor to be less than the safety speed threshold, it is possible to ensure that the vehicle completes the starting steering at a steady speed, thereby further improving the safety of the vehicle.

[0122] In some embodiments, the control method further includes: between the first moment and the third moment, controlling the driving torque of the left front wheel of the electric vehicle 01 to be smaller than the driving torque of the right front wheel of the electric vehicle 01 .

[0123] It can be understood that in the powertrain with a dual-motor architecture, the motor controller can determine the speed corresponding to the left front wheel and the speed of the motor corresponding to the right front wheel based on the resolver signal, and distribute the torque according to the speed of the motors on both sides, so that the actual yaw moment of the vehicle is better close to the expected yaw moment, ensuring lateral stability and improving steering performance.

[0124] It can be understood that, since the speed of the right motor is higher when the electric vehicle 01 turns left, the motor controller 11 controls the torque output by the right motor to be greater than the torque output by the left motor. Similarly, since the speed of the left motor is higher when the electric vehicle turns right, the motor controller 11 controls the torque output by the left motor to be greater than the torque output by the right motor.

[0125] According to the embodiment of the present application, for an electric vehicle with a dual-motor architecture powertrain, when the vehicle starts redundant steering, the drive motor is controlled to output differentiated drive torques to the two front wheels respectively, thereby ensuring the lateral stability of the vehicle during the steering process and further improving the vehicle's handling.

[0126] In some embodiments, the control method further includes: between the first moment and the third moment, in response to the slip rate of any wheel of the electric vehicle 01 being greater than a preset slip rate, controlling the corresponding drive motor of any wheel to reduce the torque output. Between the first moment and the third moment, in response to the slip rate of any wheel of the electric vehicle 01 being less than the preset slip rate, controlling the corresponding drive motor of any wheel to increase the torque output.

[0127] The slip ratio is the proportion of the sliding component in the wheel motion when there is relative motion between the wheel and the ground. Figure 5 As shown, the dotted line represents the preset slip ratio, and the solid line represents the actual slip ratio. When the slip ratio deviates from the preset slip ratio, the torque output by the driving motor also changes accordingly.

[0128] Exemplarily, taking the left front wheel of the electric vehicle 01 as an example, when the slip rate of the left front wheel LF is greater than the preset slip rate, the motor controller can control the drive motor corresponding to the left front wheel LF to reduce the torque output so that the slip rate of the left front wheel LF is reduced to the preset slip rate; when the slip rate of the left front wheel LF is less than the preset slip rate, the motor controller can control the drive motor corresponding to the left front wheel LF to increase the torque output so that the slip rate of the left front wheel LF is increased to the preset slip rate.

[0129] It should be emphasized that the closed-loop control of the wheel slip rate mentioned above can be implemented by the motor controller provided in the implementation of this application.

[0130] In the embodiment of the present application, the motor controller in the drive system can calculate the slip rate of the wheel driven by the drive motor according to the speed of the driven drive motor and the output torque of the drive motor. In this way, the observation of whether the wheel is slipping and the adjustment of the slip rate of the wheel are both realized inside the drive system, with a shorter time delay, and can almost achieve microsecond (us) level fast observation and millisecond (ms) level torque adjustment.

[0131] In some embodiments, the method also includes: after the first moment, in response to the accelerator pedal opening decreasing to less than the preset opening, or the brake pedal opening of the electric vehicle 01 being greater than the preset brake opening, controlling the drive motor 12 to stop driving the electric vehicle 01.

[0132] Among them, when the opening of the accelerator pedal is reduced to less than the preset opening, it can be understood that the user has released the accelerator pedal and hopes to stop the starting process of the electric vehicle 01. When the opening of the brake pedal is greater than the preset brake opening, it can be understood that the user has stepped on the brake pedal and hopes to stop the starting process of the electric vehicle 01. At this time, in order to respond to the user's operation, the control method provided in this application will control the drive motor 12 to stop driving the electric vehicle 01. For example, if the user finds that there is an obstacle on the driving path during the starting process of the electric vehicle 01, the user can control the electric vehicle to stop starting by releasing the accelerator pedal or stepping on the brake pedal, thereby avoiding accidents.

[0133] It can be understood that when the front wheel steering mechanism is effective, after the electric vehicle 01 is in a parking state, the rear wheel steering mechanism 40 can also be controlled to return to the center position so that the rotation direction of the two rear wheels is consistent with the direction of the vehicle body, thereby reducing the wear on the rear wheel tires.

[0134] According to the embodiment of the present application, when the user wants the electric vehicle to stop, the vehicle can be stopped by releasing the accelerator pedal or stepping on the brake pedal, which is convenient and flexible. Moreover, when the vehicle control system fails to detect the decrease in the accelerator pedal opening in time, the vehicle can still be stopped according to the brake pedal opening, further improving the safety and reliability of the vehicle.

[0135] In some embodiments, the control method further includes: after the first moment, controlling the steering angle of the rear wheel steering mechanism 40 of the electric vehicle 01 to change with the change of the yaw angular velocity.

[0136] According to an embodiment of the present application, during the redundant steering process of an electric vehicle when starting, when a deviation occurs in the yaw angular velocity of the electric vehicle, the steering angle of the two front wheels of the vehicle can be kept unchanged while the rear wheel steering mechanism of the vehicle can be independently controlled to adjust the steering angle of the two rear wheels, so that the vehicle body maintains a stable yaw angular velocity, thereby avoiding unexpected lateral movement of the vehicle during the steering process. The electric vehicle can maintain a stable body posture during the steering process.

[0137] Figure 6 The figure shows a process of controlling the rear wheel steering mechanism 40 of the electric vehicle 01 to adjust the steering angle of the rear wheels of the electric vehicle 01 during the redundant steering of the electric vehicle 01 when starting. Figure 6 The broken line shown in the figure only represents the general trend of change and does not represent the specific numerical correspondence.

[0138] Before time t0, the user turns the steering wheel to the left and steps on the accelerator pedal. At time t0, the steering wheel turns to the left at a first preset angle and the accelerator pedal opening reaches a preset opening, at which time the driving motor of the electric vehicle is controlled to drive the vehicle so that the vehicle speed increases from zero, and the rear wheel steering mechanism of the vehicle is controlled to turn right.

[0139] During the period from t0 to t1, the user continues to turn the steering wheel to the left, and the angle of the rear wheel steering mechanism to turn right increases as the steering wheel angle increases. At t1, the steering wheel angle to the left reaches a second preset opening, and the vehicle's braking system is controlled to output braking force to the left rear wheel, so that the vehicle obtains a greater yaw torque.

[0140] During a period from t1 to t2, the user turns the steering wheel to control the rear wheel steering mechanism to maintain the rightward steering angle and controls the braking system to continuously output braking force to the left rear wheel, so that the vehicle obtains a stable yaw torque. At t2, the user turns the steering wheel rightward so that the leftward steering angle of the steering wheel decreases to a second preset angle, at which time the braking system of the vehicle stops outputting braking force to the left rear wheel.

[0141] During a period from time t2 to time t3, the user continues to straighten the steering wheel. At time t3, the leftward turning angle of the steering wheel is less than the first preset angle, and the rear wheel steering mechanism is controlled to straighten, completing the vehicle's starting redundant steering process.

[0142] Understandably, Figure 6 In the process shown, the front wheel steering mechanism can change with the change of the steering wheel angle, that is, the front wheel steering mechanism is effective. Alternatively, the front wheel steering mechanism can maintain a fixed angle unchanged, for example, the front wheel steering mechanism fails, which is not limited in the embodiment of the present application.

[0143] The control method is described below in conjunction with an embodiment for a vehicle driving redundant steering scenario.

[0144] In some embodiments, the control method includes: during the driving process of the electric vehicle 01, detecting the steering wheel angle of the electric vehicle 01. At the first moment after the leftward turning angle of the steering wheel increases from zero to greater than a first preset turning angle, controlling the rear wheel steering mechanism 40 of the electric vehicle 01 to turn right.

[0145] It can be understood that the description of the first preset turning angle can refer to the relevant description in the redundant scenario of vehicle starting. During the driving of the vehicle, when the user turns the steering wheel so that the steering wheel turns left by an angle greater than the first preset turning angle, it can be understood that the user expects to control the vehicle to turn left. At this time, the control method provided in the present application will control the rear wheel steering mechanism 40 to turn right, so that the vehicle establishes a yaw angular velocity to turn left.

[0146] It can be understood that the vehicle's redundant steering can be applicable to scenarios where the front-wheel steering mechanism is effective, that is, the front-wheel steering mechanism and the rear-wheel steering mechanism are coordinated to steer the vehicle, and can also be applicable to scenarios where the front-wheel steering mechanism fails, that is, by controlling the rear-wheel steering mechanism, the vehicle can be smoothly steered even under conditions where the front wheels cannot be steered.

[0147] Similarly, in some embodiments, the control method includes: during the driving process of the electric vehicle 01, detecting the steering wheel angle of the electric vehicle 01. At the first moment after the rightward turning angle of the steering wheel increases from zero to greater than a first preset turning angle, controlling the rear wheel steering mechanism 40 of the electric vehicle 01 to turn left.

[0148] According to the embodiment of the present application, during the driving process of the electric vehicle, the rear wheel steering mechanism of the vehicle is controlled to adjust the steering angle based on the steering angle of the steering wheel, so that the vehicle can control the active steering of the front and rear wheels of the vehicle when the front wheel steering mechanism is effective, and the vehicle can control the active steering of the rear wheels of the vehicle when the front wheel steering mechanism fails, thereby ensuring the safety and reliability of the steering system of the electric vehicle. Moreover, even when the front wheel steering mechanism fails, the user can still control the steering of the vehicle by turning the steering angle of the steering wheel without performing additional operations, which is conducive to improving the user's operating experience.

[0149] In some embodiments, the control method further includes: at the first moment, controlling the rear wheel steering mechanism 40 of the electric vehicle 01 to turn right, and controlling the braking system 20 of the electric vehicle 01 to brake the left rear wheel of the electric vehicle.

[0150] In other words, during the redundant steering process of the electric vehicle, the braking system can be controlled to brake the inner rear wheel and control the rear wheel steering mechanism to actively steer, so that the electric vehicle 01 can smoothly complete the steering. In these embodiments, through single-side wheel braking and active steering of the rear wheel steering mechanism, a greater yaw acceleration can be provided for the vehicle, so that the vehicle can achieve steering faster and improve the vehicle's maneuverability.

[0151] Likewise, in some embodiments, the control method further includes: at the first moment, controlling the rear wheel steering mechanism 40 of the electric vehicle 01 to turn left, and controlling the braking system 20 of the electric vehicle 01 to brake the right rear wheel of the electric vehicle 01 .

[0152] According to the embodiment of the present application, during the driving process of the electric vehicle, the rear wheel steering mechanism and the braking system of the electric vehicle are coordinated to achieve rapid and stable vehicle steering, thereby improving the vehicle's maneuverability.

[0153] In some embodiments, the control method further includes: at the first moment, when the speed of the electric vehicle 01 is greater than the preset speed, controlling the drive motor 12 of the electric vehicle 01 to reduce the torque output. At a second moment after the first moment, when the speed of the electric vehicle 01 decreases to less than the preset speed, controlling the rear wheel steering mechanism 40 to turn right, and controlling the brake system 20 to brake the left rear wheel at a third moment after the second moment.

[0154] The preset speed can be understood as a safe speed threshold. For example, the preset speed can be 80 kilometers per hour (kph) or 100 kph, without limitation.

[0155] It can be understood that when the vehicle speed is less than the preset speed, the vehicle can be turned safely by actively controlling the rear wheel steering mechanism 40. When the vehicle speed is greater than the preset speed, there may be risks in controlling the rear wheel steering mechanism 40 to turn, so it is necessary to actively control the drive motor 12 to reduce the torque output to slow down the vehicle, and control the rear wheel steering mechanism 40 to complete the turning after the vehicle speed is less than the preset speed.

[0156] Similarly, in some embodiments, the control method further includes: at the first moment, when the speed of the electric vehicle 01 is greater than the preset speed, controlling the drive motor 12 of the electric vehicle 01 to reduce the torque output. At a second moment after the first moment, when the speed of the electric vehicle 01 decreases to less than the preset speed, controlling the rear wheel steering mechanism 40 to turn left, and controlling the brake system 20 to brake the right rear wheel at a third moment after the second moment.

[0157] According to an embodiment of the present application, during redundant steering of a vehicle, the rear-wheel steering mechanism is restricted to steering only when the vehicle speed is within a safe speed range, thereby ensuring that the vehicle can complete steering safely and smoothly, further improving the safety of the vehicle.

[0158] In some embodiments, the control method also includes: after the first moment, when the front wheel steering mechanism of the electric vehicle 01 fails, controlling the speed of the electric vehicle 01 not to change with the change of the opening of the accelerator pedal when the opening of the accelerator pedal of the electric vehicle 01 is greater than the preset acceleration opening.

[0159] It can be understood that when the accelerator pedal opening is less than or equal to the preset accelerator opening, the electric vehicle 01 can travel within the safe speed range. That is, when the front wheel steering mechanism of the electric vehicle 01 is detected to be in failure, the speed of the electric vehicle is controlled to maintain a constant rate or a preset rate, and the speed of the electric vehicle is controlled not to increase with the increase of the accelerator pedal opening, thereby ensuring the stability and reliability of the electric vehicle 01 during the U-turn process.

[0160] According to an embodiment of the present application, during redundant steering of the vehicle, when failure of the front wheel steering mechanism of the vehicle is detected, the power output of the vehicle will be actively limited, thereby limiting the speed of the electric vehicle and ensuring the safety of the steering of the electric vehicle 01.

[0161] It should be emphasized that the control method in the vehicle starting redundant steering scenario can also be used in combination with the control method in the vehicle driving redundant steering scenario, which will not be elaborated here.

[0162] Figure 7 The figure shows a process of controlling the rear wheel steering mechanism 40 of the electric vehicle 01 to adjust the steering angle of the rear wheels of the electric vehicle 01 during the redundant steering of the electric vehicle 01 when starting. Figure 7 The broken line shown in the figure only represents the general trend of change and does not represent the specific numerical correspondence.

[0163] Before time t0, the user turns the steering wheel to the left. At time t0, the steering wheel turns to the left at a first preset angle. Since the speed of the electric vehicle 01 is greater than the preset speed at this time, the drive motor of the electric vehicle is first controlled to reduce the torque output to reduce the speed of the electric vehicle.

[0164] During the period from t0 to t1, the user stops turning the steering wheel and keeps the accelerator pedal open, and the speed of the electric vehicle 01 decreases. At t1, the speed of the electric vehicle 01 decreases to a preset speed, and the rear wheel steering mechanism is controlled to turn right, so that the vehicle establishes a yaw angular velocity.

[0165] At time t2, the user returns the steering wheel to the right so that the steering wheel's turning angle to the left is reduced to less than the first preset angle. At this time, the rear wheel steering mechanism is controlled to return to the center, completing the vehicle's redundant steering process.

[0166] Understandably, Figure 7 In the process shown, the front wheel steering mechanism can change with the change of the steering wheel angle, that is, the front wheel steering mechanism is effective. Alternatively, the front wheel steering mechanism can maintain a fixed angle unchanged, for example, the front wheel steering mechanism fails, which is not limited in the embodiment of the present application.

[0167] It should be emphasized that in the embodiment of the present application, the motor controller 11 in the drive system 10 can directly control the rear wheel steering mechanism 40 of the vehicle to adjust the steering angle of the two rear wheels. That is, the motor controller 11 is used to control the drive motor 12 of the electric vehicle 01 to output torque to drive the electric vehicle 01 to travel. During the process of redundant steering when the electric vehicle 01 starts or redundant steering when traveling, the motor controller 11 is also used to control the rear wheel steering mechanism 40 of the electric vehicle 01 to adjust the steering angle of the rear wheels of the electric vehicle 01 to change with the change of the steering wheel angle of the electric vehicle 01.

[0168] In an embodiment of the present application, during the starting or driving of the electric vehicle 01, the motor controller can obtain the steering wheel angle, accelerator pedal opening and actual yaw angular velocity of the electric vehicle to control the rear wheel steering mechanism and / or braking system of the electric vehicle 01, so that the electric vehicle can complete redundant steering, thereby improving the safety and reliability of the electric vehicle's steering performance.

[0169] In some embodiments, Figure 8 As shown, the motor controller 11 includes an observer 111, a dynamics calculation module 112, and a drive control unit 113. The output end of the observer 111 is connected to the input end of the dynamics calculation module 112, the output end of the dynamics calculation module 112 is respectively connected to the drive control unit 113, the rear wheel steering mechanism of the electric vehicle 01, and the brake system of the electric vehicle 01, and the drive control unit 113 is connected to the drive motor of the electric vehicle 01.

[0170] The observer 111 is used to determine the target yaw velocity of the electric vehicle 01 during its driving process; the dynamic calculation module 112 is used to determine the yaw velocity deviation based on the received steering wheel angle and torque signal or accelerator pedal opening, combined with the target yaw velocity. After receiving the yaw velocity deviation, the calculation module 1121 outputs the steering angle of the two rear wheels to the rear-wheel steering mechanism, outputs the speed or output torque of the drive motor to the drive control unit 113, and outputs the required braking force to the braking system of the electric vehicle 01, combined with the steering wheel angle output when the steering wheel is turned.

[0171] For example, Figure 8 As shown, the output and input of the drive control unit 113 form a closed loop, which can achieve closed-loop control of the slip rate of the wheel. When the actual slip rate of the wheel is greater than the preset slip rate or less than the preset slip rate, the output torque of the drive motor is actively adjusted to make the slip rate of the wheel reach the preset slip rate, so that the electric vehicle 01 can maintain a stable speed during starting or driving.

[0172] In the embodiment of the present application, the electric vehicle 01 can be a four-motor driven electric vehicle, a three-motor driven electric vehicle or a two-motor driven electric vehicle. Exemplarily, when the electric vehicle 01 is a four-motor driven electric vehicle, the electric vehicle 01 includes four motor controllers and four drive motors, and the four motor controllers are used to control the four drive motors respectively, and each of the four drive motors can drive one wheel of the electric vehicle 01 respectively. When the electric vehicle 01 is a three-motor driven electric vehicle, the electric vehicle 01 includes three motor controls and three drive motors, and the three motor controllers are used to control the three drive motors respectively, and two of the three drive motors are used to drive two coaxial wheels respectively, and another of the three drive motors is used to drive the other two coaxial wheels at the same time. When the electric vehicle 01 is a two-motor driven electric vehicle, the electric vehicle 01 includes two motor controls and two drive motors, and the two motor controllers are used to control the two drive motors respectively, and each drive motor is used to drive two front wheels or two rear wheels respectively. Furthermore, when the drive motor is used to drive one of the wheels of the electric vehicle 01, the slip rate described above may be the slip rate of the one wheel; when the drive motor is used to drive two coaxial wheels of the electric vehicle 01, the slip rate described above may be the slip rate of the two coaxial wheels.

[0173] The motor controller provided in the embodiment of the present application can be any one of the motor controllers in the above-mentioned four-motor driven electric vehicle, or any one of the motor controllers in the above-mentioned three-motor driven electric vehicle, or any one of the motor controllers in the above-mentioned two-motor driven electric vehicle, and the embodiment of the present application does not make specific limitations on this.

[0174] The above is only a specific implementation of the present application, but the protection scope of the present application is not limited thereto. Any person skilled in the art who is familiar with the present technical field can easily think of changes or substitutions within the technical scope disclosed in the present application, which should be included in the protection scope of the present application. Therefore, the protection scope of the present application should be based on the protection scope of the claims.

Claims

1. A control method for an electric vehicle, characterized in that: The control method is used to realize redundant steering when starting an electric vehicle, and the control method comprises: Detecting the accelerator pedal opening and steering wheel angle of the electric vehicle; At the first moment after the accelerator pedal opening of the electric vehicle increases from zero to greater than a preset opening and the steering wheel turning angle to the left increases from zero to greater than a first preset turning angle, the drive motor of the electric vehicle is controlled to drive the electric vehicle and the rear wheel steering mechanism of the electric vehicle is controlled to turn right.

2. The control method according to claim 1, characterized in that: The control method further comprises: At the first moment, the rear wheel steering mechanism of the electric vehicle is controlled to turn right and the braking system of the electric vehicle is controlled to brake the left rear wheel of the electric vehicle.

3. The control method according to claim 1, characterized in that: The control method further comprises: At a second moment after the first moment, the steering wheel turns leftwards to a value greater than a second preset angle, controlling the rear wheel steering mechanism of the electric vehicle to turn right and controlling the braking system of the electric vehicle to brake the left rear wheel of the electric vehicle.

4. The control method according to claim 3, characterized in that: The control method further comprises: At a third moment after the second moment, the leftward turning angle of the steering wheel decreases to be less than the second preset turning angle, and the braking system is controlled to stop braking the left rear wheel; At a fourth moment after the third moment, the leftward turning angle of the steering wheel is reduced to be smaller than the first preset turning angle, and the rear-wheel steering mechanism is controlled to return to the center position.

5. The control method according to claim 4, characterized in that: The control method further comprises: Between the second moment and the third moment, the braking force output by the braking system to the left rear wheel is controlled to increase as the accelerator pedal opening increases, and the steering angle of the rear wheel steering mechanism is controlled to increase as the steering angle of the steering wheel increases.

6. The control method according to claim 4, characterized in that: The control method further comprises: Between the first moment and the third moment, the rotation speed of the driving motor is controlled to be less than a preset rotation speed.

7. The control method according to claim 4, characterized in that: The control method further comprises: Between the first moment and the third moment, the driving torque of the left front wheel of the electric vehicle is controlled to be smaller than the driving torque of the right front wheel of the electric vehicle.

8. The control method according to claim 4, characterized in that: The control method further comprises: Between the first moment and the third moment, in response to a slip rate of any wheel of the electric vehicle being greater than a preset slip rate, controlling a drive motor corresponding to any wheel to reduce torque output; Between the first moment and the third moment, in response to a slip ratio of any wheel of the electric vehicle being less than the preset slip ratio, the drive motor corresponding to the any wheel is controlled to increase torque output.

9. The control method according to claim 4, characterized in that: The control method further comprises: Between the first moment and the third moment, in response to the accelerator pedal opening decreasing to less than the preset opening, or the brake pedal opening of the electric vehicle being greater than the preset brake opening, the drive motor is controlled to stop driving the electric vehicle.

10. A control method for an electric vehicle, characterized in that: The control method is used to realize redundant steering of an electric vehicle, and the control method comprises: During the driving of the electric vehicle, detecting a steering wheel angle of the electric vehicle; At a first moment after the leftward turning angle of the steering wheel increases from zero to greater than a first preset turning angle, the rear wheel steering mechanism of the electric vehicle is controlled to turn right.

11. The control method according to claim 10, characterized in that: The control method further comprises: At the first moment, the rear wheel steering mechanism of the electric vehicle is controlled to turn right, and the braking system of the electric vehicle is controlled to brake the left rear wheel of the electric vehicle.

12. The control method according to claim 10, characterized in that: The control method further comprises: At the first moment, when the speed of the electric vehicle is greater than a preset speed, controlling the driving motor of the electric vehicle to reduce torque output; At a second moment after the first moment, the speed of the electric vehicle decreases to less than the preset speed, the rear-wheel steering mechanism is controlled to turn right, and at a third moment after the second moment, the braking system of the electric vehicle is controlled to brake the left rear wheel of the electric vehicle.

13. The control method according to any one of claims 10 to 12, characterized in that: The control method further comprises: After the first moment, when the front wheel steering mechanism of the electric vehicle fails, the speed of the electric vehicle is controlled not to change with the change of the opening of the accelerator pedal when the opening of the accelerator pedal of the electric vehicle is greater than the preset acceleration opening.

14. A controller for an electric vehicle, characterized in that: The controller is used to execute the control method according to any one of claims 1 to 9, or to execute the control method according to any one of claims 10 to 13.

15. An electric vehicle, characterized in that: The electric vehicle comprises a rear-wheel steering mechanism and a controller as claimed in claim 14, wherein the controller is used to control the steering of the rear-wheel steering mechanism.

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